High resolution distributed temperature sensing for downhole monitoring

Patent metadata

Field	Value
Publication number	US-10316643-B2
Application number	US-201314062547-A
Country	US
Kind code	B2
Filing date	Oct 24, 2013
Priority date	Oct 24, 2013
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A method, system and computer-readable medium for obtaining a temperature profile of a wellbore is disclosed. Raw temperature data are obtained from the wellbore using a distributed temperature sensing system. The raw temperature data includes noise. A numerical decomposition is performed on the raw temperature data within a dynamic window in a measurement space of the raw temperature data to obtain decomposition terms of order of first order and higher. An adaptive filter is applied to the decomposition terms of first order and higher within the dynamic window to reduce noise from the decomposition terms of first order and higher. The filtered decomposition terms of first order and higher are used to obtain a temperature profile of the wellbore.

First claim

What is claimed is:

1. A method of identifying a reaction of a fluid in a wellbore, comprising:
introducing the fluid into a formation;
propagating light through a dual ended cable of a distributed temperature sensor system extending along a member in the wellbore in a forward direction to obtain a first raw temperature data from the wellbore;
propagating light through the dual ended cable in a backward direction to obtain a second raw temperature data from the wellbore, the first and second raw temperature data being indicative of the reaction of the fluid with the formation and including noise;
performing a first numerical decomposition of the first raw temperature data within a first dynamic window in measurement space of the first raw temperature data to obtain first decomposition terms of first order and higher;
applying a first adaptive filter to the first dynamic window to reduce noise from the first decomposition terms of first order and higher from the first raw temperature data to obtain first filtered decomposition terms of first order and higher;
performing a second numerical decomposition of the second raw temperature data within a second dynamic window in measurement space of the second raw temperature data to obtain second decomposition terms of first order and higher;
applying a second adaptive filter to the second dynamic window to reduce noise from the second decomposition terms of first order and higher from the second raw temperature data to obtain second filtered decomposition terms of first order and higher;
correcting a depth misalignment between the first raw temperature data and the second raw temperature data using a cross-correlation of the first raw temperature data and the second raw temperature data;
using at least one of the first filtered decomposition terms of first order and higher and the second filtered decomposition terms of first order and higher to display a profile of temporal thermal gradient values on a graph of wellbore depth vs. time; and
identifying the reaction of the fluid with the formation from the profile of temporal thermal gradient.

2. The method of claim 1 , further comprising using the profile of temporal thermal gradient to determine at least one of: (i) a wellbore operation; (ii) a geologic event; (iii) a well integrity issue; (iv) a flow assurance problem; and (v) a status of downhole flow control devices.

3. The method of claim 1 , wherein the first raw temperature data and the second raw temperature data further comprises spatio-temporal temperature measurements obtained over a selected depth interval of the wellbore.

4. The method of claim 1 , wherein the first decomposition terms of first order and higher and the second decomposition terms of first order and higher represent at least one of: a gradient of temperature versus depth; a gradient of temperature versus time; a variance of temperature with respect to depth; a variance of temperature with respect to time; and a variance of temperature with respect to both depth and time.

5. The method of claim 1 , further comprising increasing a resolution of the first and second raw temperature measurements by two orders of magnitude.

6. A system for identifying a reaction of a fluid in a formation at a downhole location, comprising:
a tubing for introduction of the fluid into the formation;
a distributed temperature system comprising a dual ended cable and an optical interrogator, and configured to propagate light in the dual ended cable in a forward direction and a backward direction, the distributed temperature system configured to obtain first raw temperature data from the downhole location from the propagation of the light in the forward direction and a second raw temperature data from the downhole location from the propagation of the light in the backward direction, wherein the first and second raw temperature data is indicative of the reaction of the fluid with the formation and includes noise; and
a processor configured to:
perform a first numerical decomposition of the first raw temperature data within a first dynamic window in measurement space of the first raw temperature data to obtain first decomposition terms of first order and higher;
apply a first adaptive filter to the first dynamic window to reduce noise from the first decomposition terms of first order and higher from the first raw temperature data to obtain first filtered decomposition terms of first order and higher; and
perform a second numerical decomposition of the second raw temperature data within a second dynamic window in measurement space of the second raw temperature data to obtain second decomposition terms of first order and higher;
apply a second adaptive filter to the second dynamic window to reduce noise from the second decomposition terms of first order and higher from the second raw temperature data to obtain second filtered decomposition terms of first order and higher;
correct a depth misalignment between the first raw temperature data and the second raw temperature data using a cross-correlation of the first raw temperature data and the second raw temperature data; and
use at least one of the first filtered decomposition terms of first order and higher and the second filtered decomposition terms of first order and higher to display a profile of temporal thermal gradient values on a graph of wellbore depth vs. time; and
identify the reaction of the fluid with the formation from the profile of temporal thermal gradient.

7. The system of claim 6 , wherein the processor is further configured to use the profile of temporal thermal gradient to determine at least one of: (i) a wellbore operation; (ii) a geologic event; (iii) a well integrity issue; (iv) a flow assurance problem; and (v) a status of downhole flow control devices.

8. The system of claim 6 , wherein the first and second raw temperature data further comprises spatio-temporal temperature measurements obtained over a selected depth interval of the wellbore.

9. The system of claim 6 , wherein the first decomposition terms of first order and higher and the second decomposition terms of first order and higher represent at least one of: a gradient of temperature versus depth; a gradient of temperature versus time; a variance of temperature with respect to depth; a variance of temperature with respect to time; and a variance of temperature with respect to both depth and time.

10. The system of claim 6 , further comprising increasing a resolution of the first and second raw temperature measurements by two orders of magnitude.

11. A non-transitory computer-readable medium having instructions stored thereon that are accessible to a processor and enable the processor to perform a method for identifying a reaction of a fluid at a downhole location, the method comprising:
propagating light through a dual ended cable of a distributed temperature sensor system extending along a member in a wellbore in a forward direction to obtain a first raw temperature data from the wellbore;
propagating light through the dual ended cable in a backward direction to obtain a second raw temperature data from the wellbore, the first raw temperature data and the second raw temperature data being indicative of the reaction of the fluid with a formation and including noise;
performing a first numerical decomposition of the first raw temperature data within a first dynamic window in measurement space of the first raw temperature data to obtain first decomposition terms of first order and higher;
applying a first adaptive filter to the first dynamic window to reduce noise from the first decomposition terms of first order and higher for the first raw temperature data to o

Assignees

• Chen Jeff
• Baker Hughes A Ge Co Llc

Inventors

• Chen Jeff

Classifications

• E21B47/135

  using light waves, e.g. infrared or ultraviolet waves · CPC title

• E21B47/07 Primary

  Temperature · CPC title

• E21B47/00 Primary

  Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) · CPC title

• E21B47/123

  Fixed Constructions · mapped topic

• E21B47/065 Primary

  Fixed Constructions · mapped topic